Bodily fluids are collected for various reasons, including diagnosing illness, simple therapeutic removal, determining pregnancy, confirming or establishing levels of therapeutic agents, determining drug abuse, and profiling DNA composition. Blood, urine, and saliva are among the commonly collected bodily fluids for some or all of these purposes. Among these, saliva has an advantage over other fluids for ease of collection. This is especially true for drugs-of abuse-testing and for DNA testing.
Screening for drugs of abuse is performed by health professionals, law enforcement personnel, and government or private employers, among others. Substances of abuse that are commonly screened for include alcohol, cannabis, barbiturates, opiods, cocaine, amphetamines, and hallucinogens. For many such tests and testing environments, blood or urine collection is difficult, if not impossible, making saliva collection an appealing alternative. Saliva is less invasive to obtain than either blood or urine, and does not invoke privacy concerns to the same extent as does urine.
DNA testing is used for purposes of paternity, genealogy, disease susceptibility, and forensics, among others. Blood samples, buccal swabs, and saliva are commonly used for DNA tests. Collecting saliva is less invasive than collecting blood, and saliva collection can provide a larger, and therefore perhaps more reliable sample than buccal swabs.
Saliva samples are commonly collected by one of two methods: intra-oral sponge absorption and direct expectoration. An example of the first is U.S. Pat. No. 4,580,577 to O'Brien, et al., which discloses an absorbent mass that is masticated by the donor until saturated. The mass is placed in a squeezing device to expel saliva into a holding chamber, out of which a test aliquot can be removed. Sponge or sponge-like absorption methods are disclosed in numerous other patents, teaching variations such as added reagents, salivation promoters, preservatives, flavorings, chemical stabilizers, and a plurality of samples, among others.
A flaw of many saliva collection devices that use a sponge for collection is the inability to ascertain adequate sample size. Instructing a donor to “saturate” the sponge is ambiguous and not quantitative. Not only can this result in too little saliva for the intended subsequent use, but also in an unknown amount, even if above a minimum. For some uses such as, for example, chemical assay, a known volume is preferred over a “minimum” volume because the assay may require a relatively accurate volume. Just as important, collecting saliva is a relatively slow process. Unlike urine or blood, for example, saliva is not “cached” by the donor, and must be collected as it is produced. Therefore, it is extremely important not to collect more saliva than is required for subsequent use because this wastes time and adds stress to the persons involved in the collection process.
A volume adequacy indicator for use in sponge-type saliva collectors is disclosed in several prior art patents. U.S. Pat. No. 5,260,031 to Seymour, for example, discloses an integrated indicator that provides a visual cue that the sponge is adequately saturated. Another, similar device is disclosed in U.S. Pat. No. 6,423,550 to Jenkins, et al. Several commercially available devices include volume adequacy indicators that use dyes that either change color or are transported to a visually different place upon contact with saliva, which is read by the user as a volume adequacy indicator. One example of a commercially available device is the Quantisal™ device from Immunalysis, which corresponds to U.S. Pat. No. 5,260,031 to Seymour. Another example is the Oral-Eze® device from Quest Diagnostics®, which corresponds to U.S. Pat. No. 5,334,502 to Sangha.
The prior art volume indicators employed by sponge-type saliva collection devices require additional substituent components, including coloring dyes. These components add cost and, potentially, contaminate the collected specimen. Moreover, they often indicate only that a minimum volume has been collected, and not a specifically desired volume.
Just as important, sponge-based saliva collection itself has significant drawbacks. The sponge or sponge-like materials can adsorb saliva constituents, which may cause errors in subsequent analysis. The absorbent materials can cause discomfort for the donor, perhaps even precipitating a biological reaction. Placing and holding the sponge and sponge assembly into and in the mouth can be unpleasant for donors.
An example of a sample collection device based on direct expectoration is disclosed in U.S. Pat. No. 3,518,164 to Andelin, et al. This device includes a tube-like collector, an attached funnel, a stabilizing base, and a threaded sealing cap. The donor spits into the funnel, saliva collects in the tube, the funnel is removed, and the donated sample is sealed with the cap. In this invention, the collected volume is determined by reading the fluid meniscus against inscribed markings on the tube, similar to an ordinary graduated cylinder.
Other prior art example patents, which teach variations of direct saliva expectoration collection, and with sample volume indicators include:    U.S. Patent App. No. 20090216213 to Muir et al.    U.S. Pat. No. 4,283,498 to Schlesinger    U.S. Pat. No. 4,589,548 to Fay    U.S. Pat. No. 4,761,379 to Williams, et al.    U.S. Pat. No. 4,768,238 to Kleinberg, et al.    U.S. Pat. No. 4,932,081 to Burns
All of these devices have inscribed markings on the container analogous to a graduated cylinder.
While container gradations are relatively common as volume indicators, and are usually accurate enough, reading them correctly can challenge device users. Proper technique requires that the fluid meniscus be discerned and aligned with the gradations, but discerning a fluid meniscus is not always simple, especially in challenging situations (low light, high stress, time-constrained). A consequence can be an erroneous volume reading, either too little or too much.
Therefore, there is a need for a saliva container that is a receptacle for neat saliva, and that has an unambiguous, easy-to-read indicator of saliva volume.